In recent years, component transfusion of transfusing only the component necessary for a patient is being widely carried out. When carrying out such component transfusion, a blood bag system for dividing the blood (whole blood) sampled from a donor to a plurality of blood components, and accommodating and preserving the same is used.
In this type of blood bag system, a predetermined amount of blood (initial flow blood) that flows out immediately after inserting a blood sampling needle into the donor is accommodated in an initial flow blood bag, and the initial flow blood in the initial flow blood bag is transferred to a blood sampling holder with a blood sampling device to be used as a test blood for blood transfusion.
The blood sampling device includes, for example, a tubular blood sampling holder to which the blood sampling tube can be inserted, a hollow needle that can penetrate through a rubber plug (plug member) of the blood sampling tube, a hub that supports a base end side of the hollow needle and to which the blood sampling holder is attached, and a needle cover made of rubber that is externally fitted to the hub while covering the tip side of the hollow needle.
In this type of blood sampling device, when the blood sampling tube is inserted into the blood sampling holder, the needle cover is pushed and contracted in a longitudinal direction by the rubber plug of the blood sampling tube, and the hollow needle is exposed from the needle cover thus penetrating through the rubber plug. In this case, the needle cover is elastically deformed to an accordion form (waveform) so that a diameter becomes larger toward a radially outer side of the hollow needle, whereby the externally fitted portion of the needle cover with respect to the hub bulges and the fit-in force of the needle cover and the hub lowers.
The distal end portion of the needle cover may bite into the through-hole formed in the rubber plug, where if the blood sampling tube is pulled out from the hollow needle in such a state, the needle cover may be pulled by the rubber plug and fall out from the hub, and the initial flow blood may leak out from the blood sampling device as a result.
For the blood sampling device that solves such problem, the blood sampling device that prevents leakage of the initial flow blood (blood) from the blood sampling device by fixing a plate for preventing the accordion-like elastic deformation of the needle cover from reaching the externally fitted portion when the hollow needle is penetrated through the rubber plug of the blood sampling tube to the blood sampling holder (see e.g., JP 2012-16496 A) is known.
The blood sampling device in which a tubular body that surrounds the hub is arranged integrally with respect to the blood sampling holder, and the distal end portion of the tubular body is gradually diameter-reduced toward the needle tip side to be proximate to the externally fitted portion of the needle cover thus suppressing the needle cover from falling out from the hub is known (see e.g., U.S. Pat. No. 7,435,231).